A SpaceX Falcon 9 rocket blasted off from Florida on Friday to send a hefty communications satellite on its way to a high-altitude orbit, then turned around and gently settled itself on a platform in the ocean.

SpaceX had downplayed chances the returning first-stage would nail the landing, despite a successful touchdown on May 6 by another rocket on a similarly challenging satellite-delivery mission.

SpaceX's first successful landing was on the ground at Cape Canaveral Air Force Station in Florida in December. That rocket is expected to become a showpiece at SpaceX's Hawthorne, California, headquarters.

The rocket flying on Friday carried a 6,600-pound commercial communications satellite for Thaicom.

The launch was the fifth of more than a dozen SpaceX plans to fly this year.